RE: [TCML] my medium sized tesla problem

["Lau, Gary" <Gary.Lau@xxxxxx>]

Hi Mike,

If I understand your circuit correctly, it sounds like you have the cap and gap reversed from what is generally recommended.  This is bad for two reasons.  First, if the gap is too wide or there is some other fault in the gap/primary wiring, it leaves the cap in parallel with the NST, free to mains-resonate to self-destruction without limits imposed by a functional spark gap.  And second, even if all is well, the NST will be subject to a greater level of high-voltage RF than if the gap were in parallel with the NST.  But none of this explains why your gap doesn't fire.  Both circuit configurations would give the same performance and gap-firing behavior.

The likely problems are:

1) Your NST is toast.  This may have been caused by operating the NST in parallel with the cap and having the spark gap too wide (see first reason, previous paragraph).  Can you draw an arc between the two NST HV terminals with nothing else connected?  

2) Are you sure the NST is a core-and-coil type and not a lightweight electronic (high frequency) type?  The electronic ones are unsuitable for Tesla coils.

3) The gap is too wide to fire.  How wide is it?  

4) Your cap is toast.  How do you know it's good?  Even if it tests OK with a capacitance meter or Ohmmeter, it may break down under high voltage.  It's true that MMC's are less likely to be shorted-bad than other cap types, unless you've been extremely brutal with it, but there could also be wiring shorts within the array.

5) Any number of other silly wiring errors.

Regards, Gary Lau
MA, USA



> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of mike osipowicz
> Sent: Thursday, August 13, 2009 9:30 PM
> To: tesla@xxxxxxxxxx
> Subject: [TCML] my medium sized tesla problem
> 
> 
> hey everybody, I am having serious problems with my medium sized tesla coil.here
> is what im running; 10kv 30 ma nst, an mmc made up of 16 1.6kv .22 uf caps, for
> 13.6 nf's of capacitance, primary is 11 turns of 1/4 inch copper tubing, tapped
> wherever needed, my secondary is 1100 turns of 26 gauge magnet wire, with no
> gaps or shorts, my toroid is home made with plastic containers covered in tin foil to
> look and perform like a professional one, my spark gap is two bolts lined up in a 4
> inch pvc pipe, my PROBLEM is when I fire it up with the caps in parallel with my
> nst, and my spark gap in series with the nst and my primary coil, my spark gap
> DOES NOT FIRE!... the caps are good, everything is good, I cant figure this stupid
> thing out!

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla